3,411 research outputs found
Effects of Cold-formed Steel Framed Gypsum Partition Walls on the Seismic Response of a Medical Facility
The first experimental phase of the NEES Nonstructural Grand Challenge Project: âSimulation of the Seismic Performance of Nonstructural Systemsâ investigated the in-plane hysteretic behaviors of thirty-six full-scale cold-formed steel framed gypsum partition walls. Results of quasi-static reverse cyclic and dynamic testing on sixteen wall configurations including walls with commercial and institutional construction details and innovative connection techniques are first briefly reviewed. Thereafter, six tri-linear hysteretic models of partition walls with pinching behavior and strength and stiffness degradation are developed based on the experimental data for use in a finite element analysis platform. The partition wall models, represented by shear spring elements at each floor level, are incorporated into a numerical model of a four story steel moment frame medical facility. Although nonstructural components are required to carry self-imposed loads and minimal external loads and are not required to be considered in the structural analysis and design of buildings, the addition of the partition walls are shown to increase the stiffness and strength of the building, reducing the natural period by more than 11%. Furthermore, partition walls are shown to introduce over 42% more damping into the building due to the continual energy dissipation through their pinched hysteretic behaviors. The effect of the nonstructural partition walls on the inter-story displacements and absolute accelerations is also examined
ISOCAM observations of the L1551 star formation region
The results of a deep mid-IR ISOCAM survey of the L1551 dark molecular cloud
are presented. The aim of this survey is a search for new YSO (Young Stellar
Object) candidates, using two broad-band filters centred at 6.7 and 14.3
micron. Although two regions close to the centre of L1551 had to be avoided due
to saturation problems, 96 sources were detected in total (76 sources at 6.7
micron and 44 sources at 14.3 micron). Using the 24 sources detected in both
filters, 14 were found to have intrinsic mid-IR excess at 14.3 micron and were
therefore classified as YSO candidates. Using additional observations in B, V,
I, J, H and K obtained from the ground, most candidates detected at these
wavelengths were confirmed to have mid-IR excess at 6.7 micron as well, and
three additional YSO candidates were found. Prior to this survey only three
YSOs were known in the observed region (avoiding L1551 IRS5/NE and HL/XZ Tau).
This survey reveals 15 new YSO candidates, although several of these are
uncertain due to their extended nature either in the mid-IR or in the
optical/near-IR observations. Two of the sources with mid-IR excess are
previously known YSOs, one is a brown dwarf MHO 5 and the other is the well
known T Tauri star HH30, consisting of an outflow and an optically thick disk
seen edge on.Comment: 14 Pages, 8 Figure
ISOCAM observations of the rho Ophiuchi cloud: Luminosity and mass functions of the pre-main sequence embedded cluster
We present the results of the first extensive mid-infrared (IR) imaging
survey of the rho Ophiuchi embedded cluster, performed with the ISOCAM camera
on board the ISO satellite. The main molecular cloud L1688, as well as L1689N
and L1689S, have been completely surveyed for point sources at 6.7 and 14.3
micron. A total of 425 sources are detected including 16 Class I, 123 Class II,
and 77 Class III young stellar objects (YSOs). Essentially all of the mid-IR
sources coincide with near-IR sources, but a large proportion of them are
recognized for the first time as YSOs. Our dual-wavelength survey allows us to
identify essentially all the YSOs with IR excess in the embedded cluster down
to Fnu ~ 10 - 15 mJy. It more than doubles the known population of Class II
YSOs and represents the most complete census to date of newly formed stars in
the rho Ophiuchi central region. The stellar luminosity function of the
complete sample of Class II YSOs is derived with a good accuracy down to L=
0.03 Lsun. A modeling of this lumino- sity function, using available pre-main
sequence tracks and plausible star for- mation histories, allows us to derive
the mass distribution of the Class II YSOs which arguably reflects the IMF of
the embedded cluster. We estimate that the IMF in rho Ophiuchi is well
described by a two-component power law with a low- mass index of -0.35+/-0.25,
a high-mass index of -1.7 (to be compared with the Salpeter value of -1.35),
and a break occurring at M = 0.55+/-0.25 Msun. This IMF is flat with no
evidence for a low-mass cutoff down to at least 0.06 Msun.Comment: A&A Document Class -- version 5.01, 27 pages, 10 figures v2: typos
added including few changes in source numberin
AMI observations of Lynds Dark Nebulae: further evidence for anomalous cm-wave emission
Observations at 14.2 to 17.9 GHz made with the AMI Small Array towards
fourteen Lynds Dark Nebulae with a resolution of 2' are reported. These sources
are selected from the SCUBA observations of Visser et al. (2001) as small
angular diameter clouds well matched to the synthesized beam of the AMI Small
Array. Comparison of the AMI observations with radio observations at lower
frequencies with matched uv-plane coverage is made, in order to search for any
anomalous excess emission which can be attributed to spinning dust. Possible
emission from spinning dust is identified as a source within a 2' radius of the
Scuba position of the Lynds dark nebula, exhibiting an excess with respect to
lower frequency radio emission. We find five sources which show a possible
spinning dust component in their spectra. These sources have rising spectral
indices in the frequency range 14.2--17.9 GHz. Of these five one has already
been reported, L1111, we report one new definite detection, L675, and three new
probable detections (L944, L1103 and L1246). The relative certainty of these
detections is assessed on the basis of three criteria: the extent of the
emission, the coincidence of the emission with the Scuba position and the
likelihood of alternative explanations for the excess. Extended microwave
emission makes the likelihood of the anomalous emission arising as a
consequence of a radio counterpart to a protostar or a proto-planetary disk
unlikely. We use a 2' radius in order to be consistent with the IRAS
identifications of dark nebulae (Parker 1988), and our third criterion is used
in the case of L1103 where a high flux density at 850 microns relative to the
FIR data suggests a more complicated emission spectrum.Comment: submitted MNRA
Diabetes in sub-Saharan Africa: from clinical care to health policy.
Rapid demographic, sociocultural, and economic transitions are driving increases in the risk and prevalence of diabetes and other non-communicable diseases (NCDs) in sub-Saharan Africa. The impacts of these transitions and their health and economic consequences are evident. Whereas, in 1990, the leading causes of death in sub-Saharan Africa were HIV/AIDS, lower respiratory infections, diarrhoeal diseases, malaria, and vaccine-preventable diseases in children, in more recent years, cardiovascular diseases and their risk factors are replacing infectious diseases as the leading causes of death in this region, and rates of increase of cardiovascular risk factors are predicted to be greater in sub-Saharan Africa than in other parts of the world. Thus, sub-Saharan Africaâwhich contains a high proportion of the world\u27s least developed countriesâwill face the multifaceted challenge of dealing with a high burden of infectious diseases and diseases of poverty, while also addressing the increasing burden of cardiovascular disease and its risk factors. At present, many of the health systems in sub-Saharan Africa struggle to cope with infectious diseases. Meeting the goals of the UN high-level meeting on NCDs (to reduce premature mortality from NCDs by 25% by 2025) and Sustainable Development Goals (SDGs; to reduce premature mortality from NCDs by a third by 2030) requires a coordinated approach within countries, which starts with a firm consideration of disease burden, needs, and priorities
The spatio-temporal distribution of COVID-19 infection in England between January and June 2020
The spatio-temporal dynamics of an outbreak provide important insights to help direct public health resources intended to control transmission. They also provide a focus for detailed epidemiological studies and allow the timing and impact of interventions to be assessed.A common approach is to aggregate case data to administrative regions. Whilst providing a good visual impression of change over space, this method masks spatial variation and assumes that disease risk is constant across space. Risk factors for COVID-19 (e.g. population density, deprivation and ethnicity) vary from place to place across England so it follows that risk will also vary spatially. Kernel density estimation compares the spatial distribution of cases relative to the underlying population, unfettered by arbitrary geographical boundaries, to produce a continuous estimate of spatially varying risk.Using test results from healthcare settings in England (Pillar 1 of the UK Government testing strategy) and freely available methods and software, we estimated the spatial and spatio-temporal risk of COVID-19 infection across England for the first 6 months of 2020. Widespread transmission was underway when partial lockdown measures were introduced on 23 March 2020 and the greatest risk erred towards large urban areas. The rapid growth phase of the outbreak coincided with multiple introductions to England from the European mainland. The spatio-temporal risk was highly labile throughout.In terms of controlling transmission, the most important practical application of our results is the accurate identification of areas within regions that may require tailored intervention strategies. We recommend that this approach is absorbed into routine surveillance outputs in England. Further risk characterisation using widespread community testing (Pillar 2) data is needed as is the increased use of predictive spatial models at fine spatial scales
Identification of Pharmacodynamic Transcript Biomarkers in Response to FGFR Inhibition by AZD4547
The challenge of developing effective pharmacodynamic biomarkers for preclinical and clinical testing of FGFR signaling inhibition is significant. Assays that rely on the measurement of phospho-protein epitopes can be limited by the availability of effective antibody detection reagents. Transcript profiling enables accurate quantification of many biomarkers and provides a broader representation of pathway modulation. To identify dynamic transcript biomarkers of FGFR signaling inhibition by AZD4547, a potent inhibitor of FGF receptors 1, 2, and 3, a gene expression profiling study was performed in FGFR2-amplified, drug-sensitive tumor cell lines. Consistent with known signaling pathways activated by FGFR, we identified transcript biomarkers downstream of the RAS-MAPK and PI3K/AKT pathways. Using different tumor cell lines in vitro and xenografts in vivo, we confirmed that some of these transcript biomarkers (DUSP6, ETV5, YPEL2) were modulated downstream of oncogenic FGFR1, 2, 3, whereas others showed selective modulation only by FGFR2 signaling (EGR1). These transcripts showed consistent time-dependent modulation, corresponding to the plasma exposure of AZD4547 and inhibition of phosphorylation of the downstream signaling molecules FRS2 or ERK. Combination of FGFR and AKT inhibition in an FGFR2-mutated endometrial cancer xenograft model enhanced modulation of transcript biomarkers from the PI3K/AKT pathway and tumor growth inhibition. These biomarkers were detected on the clinically validated nanoString platform. Taken together, these data identified novel dynamic transcript biomarkers of FGFR inhibition that were validated in a number of in vivo models, and which are more robustly modulated by FGFR inhibition than some conventional downstream signaling protein biomarkers
Birth and Evolution of Isolated Radio Pulsars
We investigate the birth and evolution of Galactic isolated radio pulsars. We
begin by estimating their birth space velocity distribution from proper motion
measurements of Brisken et al. (2002, 2003). We find no evidence for
multimodality of the distribution and favor one in which the absolute
one-dimensional velocity components are exponentially distributed and with a
three-dimensional mean velocity of 380^{+40}_{-60} km s^-1. We then proceed
with a Monte Carlo-based population synthesis, modelling the birth properties
of the pulsars, their time evolution, and their detection in the Parkes and
Swinburne Multibeam surveys. We present a population model that appears
generally consistent with the observations. Our results suggest that pulsars
are born in the spiral arms, with a Galactocentric radial distribution that is
well described by the functional form proposed by Yusifov & Kucuk (2004), in
which the pulsar surface density peaks at radius ~3 kpc. The birth spin period
distribution extends to several hundred milliseconds, with no evidence of
multimodality. Models which assume the radio luminosities of pulsars to be
independent of the spin periods and period derivatives are inadequate, as they
lead to the detection of too many old simulated pulsars in our simulations.
Dithered radio luminosities proportional to the square root of the spin-down
luminosity accommodate the observations well and provide a natural mechanism
for the pulsars to dim uniformly as they approach the death line, avoiding an
observed pile-up on the latter. There is no evidence for significant torque
decay (due to magnetic field decay or otherwise) over the lifetime of the
pulsars as radio sources (~100 Myr). Finally, we estimate the pulsar birthrate
and total number of pulsars in the Galaxy.Comment: 27 pages, including 15 figures, accepted by Ap
An exploration of parentsâ preferences for foot care in juvenile idiopathic arthritis: a possible role for the discrete choice experiment
Background:
An increased awareness of patientsâ and parentsâ care preferences regarding foot care is desirable from a clinical perspective as such information may be utilised to optimise care delivery. The aim of this study was to examine parentsâ preferences for, and valuations of foot care and foot-related outcomes in juvenile idiopathic arthritis (JIA).<p></p>
Methods:
A discrete choice experiment (DCE) incorporating willingness-to-pay (WTP) questions was conducted by surveying 42 parents of children with JIA who were enrolled in a randomised-controlled trial of multidisciplinary foot care at a single UK paediatric rheumatology outpatients department. Attributes explored were: levels of pain; mobility; ability to perform activities of daily living (ADL); waiting time; referral route; and footwear. The DCE was administered at trial baseline. DCE data were analysed using a multinomial-logit-regression model to estimate preferences and relative importance of attributes of foot care. A stated-preference WTP question was presented to estimate parentsâ monetary valuation of health and service improvements.<p></p>
Results:
Every attribute in the DCE was statistically significant (pâ<â0.01) except that of cost (pâ=â0.118), suggesting that all attributes, except cost, have an impact on parentsâ preferences for foot care for their child. The magnitudes of the coefficients indicate that the strength of preference for each attribute was (in descending order): improved ability to perform ADL, reductions in foot pain, improved mobility, improved ability to wear desired footwear, multidisciplinary foot care route, and reduced waiting time. Parentsâ estimated mean annual WTP for a multidisciplinary foot care service was ÂŁ1,119.05.<p></p>
Conclusions:
In terms of foot care service provision for children with JIA, parents appear to prefer improvements in health outcomes over non-health outcomes and service process attributes. Cost was relatively less important than other attributes suggesting that it does not appear to impact on parentsâ preferences.<p></p>
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